Update SpecAssay Check extension to v0.4.12 (#4254)

Update specassay-check extension submitted by @rdryfoos to:
- extensions/catalog.community.json (version, download_url, description, provides.commands)
- docs/community/extensions.md community extensions table

Closes #4252

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extensions/catalog.community.json

@@ -4506,10 +4506,10 @@
     "specassay-check": {
       "name": "SpecAssay Check",
       "id": "specassay-check",
-      "description": "Gate 2 refuses silent gaps and emits a trace-manifest (trace-manifest.json).",
+      "description": "Gate 2 refuses silent gaps and emits a trace-manifest (`trace-manifest.json`).",
       "author": "Rik Dryfoos",
-      "version": "0.3.3",
-      "download_url": "https://github.com/rdryfoos/specassay/releases/download/v0.3.3/specassay-check-0.3.3.zip",
+      "version": "0.4.12",
+      "download_url": "https://github.com/rdryfoos/specassay/releases/download/v0.4.12/specassay-check-0.4.12.zip",
       "repository": "https://github.com/rdryfoos/specassay",
       "homepage": "https://www.specassay.com",
       "documentation": "https://github.com/rdryfoos/specassay/blob/main/extensions/specassay-check/README.md",
@@ -4532,7 +4532,7 @@
         ]
       },
       "provides": {
-        "commands": 1,
+        "commands": 2,
         "hooks": 1
       },
       "tags": [
@@ -4546,7 +4546,7 @@
       "downloads": 0,
       "stars": 0,
       "created_at": "2026-08-13T00:00:00Z",
-      "updated_at": "2026-08-13T00:00:00Z"
+      "updated_at": "2026-08-21T00:00:00Z"
     },
     "specjudge": {
       "name": "SpecJudge — right-size the model before you implement",